The background description provided herein is for the purpose of generally presenting the context of the disclosure. Work of the presently named inventors, to the extent it is described in this background section, as well as aspects of the description that may not otherwise qualify as prior art at the time of filing, are neither expressly nor impliedly admitted as prior art against the present disclosure.
Many communication systems including magnetic and optical recording systems, communicate a particular type of data patterns. For example, run length limited (RLL) codes include limitations such as a minimum and a maximum run length (commonly referred to as a D constraint and a K constraint, respectively). D and K constraints may be written in slash notation as a D/K constraint.
RLL codes include at least D data “0s” between consecutive data “1s” and a maximum of K data “0s” between consecutive data “1s”. For example, the Four-to-Six Modulation code has a D/K constraint of 1/10.
Data patterns having a D/K constraint of 1/10 can include pulses with a duration of two channel bit lengths, or 2T patterns, within the data patterns, where “T” corresponds to a single channel bit duration. Each “1” channel bit in the data pattern represents a polarity transition. Two polarity transitions separated by 2 channel bits (e.g. “101”) correspond to one 2T pattern.